WET weather chaos will lash parts of Australia today with heavy falls set to hit for the second day in a row.

And while storms and heavy falls are easing in the southern states, people living in parts of Queensland and New South Wales have been warned the worst isn't over yet.

Sky News Weather chief meteorologist Tom Saunders told news.com.au it has been a very wet couple of days with most capital cities copping some falls.

Mr Saunders said the worst of the conditions were easing across Tasmania, Victoria and South Australia, but other parts of the country weren't so fortunate.

"Queensland and NSW are in for some more heavy falls today," he said.

"The worst isn't over yet, we can expect more of the same conditions we saw yesterday.

"Heavy falls and more thunderstorms are expected across parts of NSW and QLD."

Mr Saunders said a tropical humid air mass was spreading across eastern Australia, which was contributing to our soggy weather pattern.

"Mudgee in NSW yesterday received its heaviest falls in seven years with 72mm of rain recorded, while Aireys Inlet (southwest of Melbourne) got its heaviest falls in more than 20 years with 90mm of rain," he said.

Meanwhile an east coast low has sent humid winds across NSW, with forecasters predicting rain or possible showers across the state for the rest of the week.

Sydneysiders can expect another soggy day after being battered overnight, with showers and storms forecast for the city, Wollongong, Newcastle and the Central Coast regions.

It comes after an afternoon of monster storms yesterday which left around 5000 residents in the Blue Mountains and western Sydney temporarily cut off from power.

Lightning strikes also forced some train commuters onto buses and delayed flights at Sydney airport, while suburbs copped a drenching.

The inner-city suburb of Marrickville copped 33mm of rain in one hour and flash flooding hit a number of suburbs with two people rescued in Arncliffe and Bexley.

The State Emergency Service received 100 calls for help across Sydney.